1eChemical formulae, equations and calculations

Syllabus objectives

• 1.25write word equations and balanced chemical equations (including state symbols): • for reactions studied in this specification • for unfamiliar reactions where suitable information is provided.
• 1.26calculate relative formula masses (including relative molecular masses) (Mr) from relative atomic masses (Ar)
• 1.27know that the mole (mol) is the unit for the amount of a substance
• 1.28understand how to carry out calculations involving amount of substance, relative atomic mass (Ar) and relative formula mass (Mr)
• 1.29calculate reacting masses using experimental data and chemical equations
• 1.30calculate percentage yield
• 1.31understand how the formulae of simple compounds can be obtained experimentally, including metal oxides, water and salts containing water of crystallisation
• 1.32know what is meant by the terms empirical formula and molecular formula
• 1.33calculate empirical and molecular formulae from experimental data
• 1.34understand how to carry out calculations involving amount of substance, volume and concentration (in mol/dm3) of solutionSeparate Chemistry only
• 1.35understand how to carry out calculations involving gas volumes and the molar volume of a gas (24 dm3 and 24 000 cm3 at room temperature and pressure (rtp))Separate Chemistry only
• 1.36practical: know how to determine the formula of a metal oxide by combustion (e.g. magnesium oxide) or by reduction (e.g. copper(II) oxide)Practical